Watch-case



F. MINK.

WATCH GASE.

(No Model.)

Patented Apr. 8, 1890.

UNITED STATES PATENT OFFICE.

FRITZ MINK, OF PHILADELPHIA, PENNSYLVANIA.

WATCH-CA3 E.

SPECIFICATION forming part of Letters Patent No. 425,383, dated April 8, 1890.

Application filed December 27, 1889- Serial No. 335,144. (No model.)

To all whom it may concern.-

Be it known that I, FRITZ MINK, of the city and county of Philadelphia, and State of Pennsylvania, have invented an Improvement in Watch- Cases, of which the following is a specification.

My invention has reference to the manufacture of watch-cases; and it consists in certain improvements which are fully set forth in the following specification and shown in the accompanying drawings, which form a part thereof.

Heretofore watch case bezels and backs have been stamped from sheet metal and formed with a projecting flange or annular rim, which is screw-threaded upon its outer surface for attachment to the center. This construction has been found objectionable, owing to the fact that the said annular rim or flange is extremely weak and liable to injury during the process of en g'ravin g the back or outer surface by the usual machinery employed. It has been customary to fill said back or bezel with cement to resist the pressure which is necessary upon the surface during the engraving operation. Difficulty has been experienced from the constructions heretofore employed, owing to the fact that this annular rim or flange, particularly when screw-threaded, was so weak that it was liable to become bent or injured during the aforesaid engraving process. To overcome this defect, I greatly increase the amount of said annular rim or flange and turn it upon itself, so as to increase the thickness, and thereby give greater solidity to said rim as an entirety. Furthermore, I am able to so form the said flanged portion which has been bent over that it shall extend backward into the back or bezel until it reaches the metal of said back or bezel, and thereby act as a support or annular support to prevent the said back or bezel being bent inward during the engraving operation or during the carrying of the watch. This latter construction would enable the use of lighter material in the back or bezel and at the same time insure the requisite solidity. This method of forming the increased stability to the annular rim or flange is much cheaper than any upsetting process.

In the drawings, Figure l is a side elevation of a watch-case back with part in section embodying my invention. Fig. 2 is an inverted plan view of same. Fig. 3 is a similar view to Fig. 1 of the bezel of the watch-case, and Fig. 4 is an inverted plan view of same.

A is the body orback of bezel, and is formed of stamped sheet metal, and is provided with the shoulder B and the annular rim or flange C,which is externally screw-threaded, as at D. This flange or rim for the process of manu facture is made of considerable length and doubling upon itself, as at E, making the said rim or flange upon the finished back or bezel of double the thickness which it would otherwise have been. In Fig. 1 this portion E, which has been bent back upon the rim 0, is of such a depth that it rests against the body portion A of the back and acts as a strut or annular support to prevent the said back being crushed in either during the engraving process or while the watch is being worn.

The bezel differs from the back merely in having the center of the body A cut out and the edges bent inward to form the reflector F and support for the glass G, as shown in Figs. 3 and 4. In Fig. 3 it will be seen that the part E of the rim is not made to extend so far up as in the case of Fig. 1; but it may, if desired, be extended to the body part A, as shown in Fig. 1. 011 the other hand, the part E of the back shown in Fig. 1 may terminate as indicated in Fig. 3. A cover or bezel of this construction permits the use of lighter sheet metal, since the weak part is re-enforeed by the addition of the part E. lIeretofore when the screw-thread D was out upon the rim or flange so much of the metal was cut away that a very weak condition was the result, giving trouble in the subsequent manipulations in finishing the case or bezel, and to prevent absolute loss it was always neces sary to use heavy sheet metal, since upsetting or thickening of the metal at this place was a commercial, if not a practical, impossibility when considering the necessity of keeping down the cost of manufacture. All of these difflcuities are overcome by the 0011- struction forming the subject-matter of this application.

I do not limit my invention to any particular kind of metal or preliminary process of forming the back or bezel, as solid or filled upon its outer surface.

metal may be used and the article may be stamped or spun into the desired construction.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. A watch-case back or bezel formed of sheet metal and having the annular rim bent backward upon itself and screw threaded 2. A watch-case back or bezel formed of sheet metal and having the annular rim bent backward upon itself and extending inward to the body of the back or bezel to form an annular support and screw-threaded upon its outer surface.

3. A watch-case back orbezel formed of the body A, provided with the annular rim 0, having the part E bent back to increase the strength and thickness of said annular rim.

4. A watch-case back or bezel formed of thin metal and having; its edge formed substantially at right angles to the body of the back or bezel and bent backward upon itself to form a thick cylindrical rim.

5. A watch-case back or bezel formed of thin metal and having its edge formed substantially at right angles to the body of the back or bezel and bent backward upon itself to form a thick cylindrical rim, and in which said rim is provided with a shoulder and an external screw-thread.

In testimony of which invention I have hcrcunto set my hand.

FRITZ MINK.

Witnesses:

II. M. KAIN, 'lnno. UANFIELD, Jr. 

